Cocaine abuse continues to impose serious medical, psychological and criminal challenges for society. A thorough understanding of the neural basis underlying the effects of cocaine is critical to the development of science-based treatment protocols for cocaine dependence. Serotonin (5-hydroxytryptamine, 5-HT) is involved in the etiology of psychotic (e.g., schizophrenia) and affective disorders (e.g., anxiety, depression) which are often experienced by cocaine abusers. The innervation and localization of 5-HT1B receptors (5-HT1BR) and 5-HT2CR in mesocorticolimbic circuits and our preliminary data support differential roles of each receptor in modulating basal and cocaine-stimulated behavior. In the present proposal, the role of 5-HT1BR and 5-HT2CR in the acute locomotor stimulant and discriminative stimulus effects of cocaine will be investigated using novel 5-HT1BR and 5-HT2CR ligands and after knockdown or overexpression of 5-HT1BR or 5-HT2CR. The pattern of immediate early gene expression in the presence vs. absence of 5-HT1BR or 5-HT2CR ligands will be employed to guide studies to localize the site of action of 5-HT1BR and 5-HT2CR, respectively. Based upon this map, microinfusions of 5-HT1BR or 5-HT2CR ligands, antisense oligonucleotides or viral vectors encoding the 5-HT1BR or 5-HT2CR will be targeted to specific mesocorticolimbic nuclei to clarify the role of brain 5-HT1BR and 5-HT2CR in basal and cocaine-evoked behaviors. Modifications in 5-HT1BR and 5-HT2CR during withdrawal from chronic cocaine will also be established via analysis of hyperactivity induced by 5-HT1BR and 5-HT2CR agonists and levels of 5-HT1BR and 5-HT2CR mRNA and protein expression, respectively. The research goal of this K02 is to pursue the development of new methodologies based on molecular biology, genomics and proteomics and the application of these methodologies to elucidate the neural mechanisms that underlie the in vivo effects of cocaine. I propose to gain further training in measures of gene expression, including DNA microarrays and "real-time" PCR, in order to establish the impact of cocaine on the steady state levels of mRNA for monoamine transporters and receptors. In addition, we will develop the skills required to conduct virally-mediated gene transfers for the overexpression of receptor proteins in specific brain circuits. The teaching goal is to expand my efforts in drug dependence education in both the academic and community arenas. These educational endeavors, exemplified by my directorship of a NIDA Training Grant in the pharmacology of abused drugs and the mentoring of junior scientists in the laboratory will be enhanced by the development of a curriculum for the training of health care professionals in the science-based treatment of drug dependence. The research administrative goal of the K02 is to continue my involvement in research initiatives in drug abuse on the campus and nationally. Thus, the release time and salary support provided by this K02 would continue to enhance the development of my career in the science of drug dependence.